复合钒钼酸干凝胶薄膜湿敏元件的感湿机理

Humidity Sensing Mechanism of Poly-vanadium-molybdenum Acid Xerogel Thin Film Humidity Elements

采用sol-gel法，制备了复合钒钼酸H2V8．5Mo3.5O32·nH2O干凝胶薄膜湿敏元件。测试频率为1kHz时，元件全湿范围内线性响应好，灵敏度高，最大湿滞约为RH2．74％，响应、恢复时间分别为8s和20s，283-303K温度范围内的感湿温度系数为RH0．4％／℃；H2V8．5Mo3．5O32·nH2O干凝胶薄膜湿敏元件的导电机理为电子和离子导电共存，低湿时以电子导电为主，湿度增加，离子导电增强。

Poly-vanadium-molybdenum acid H2V8.5Mo3.5O32·nH2O xerogel thin films humidity elements were prepared by sol-gel process. There are a better linear relationship and a high sensitivity in total RH range for H2V8.5Mo3.5O32·nH2O at 1 kHz. The hysteric is RH 2.74%. The response time and the recovery time of the described materials when the humidity increases or decreases between 33% and 85% are 8 s and 20 s, respectively. The temperature errors of the humidity in the temperature range 283～303 K is RH 0.4%/℃. The total conductance of H2V8.5Mo3.5O32·nH2O consists of electronic and ionic parts, in low RH range, the conductance is determined mainly by electronic part, the ionic conductance increases with an increase of humidity.